As part of a test program for a structure, static and fatigue tests may need to be carried out on the structure at an elevated or lowered temperature. The test specimen may be heated/cooled and subjected to a variety of imposed mechanical load scenarios. This test program may be used, for example, to test the whole or part of an aircraft structure, or any other structure.
In some circumstances, it is not practicable or necessary, to heat/cool the entire test specimen. For example, the size and geometry of the test rig supporting the specimen may hinder the use of some heating/cooling arrangements. Also, the thermal test may only be applicable to certain areas of the test specimen. For example, if the test specimen includes metallic and composite components then the thermal loading due to the thermal coefficients of the different materials may only need to be observed at the interface between these two materials.
Therefore, it can be appropriate to isolate a section of the test specimen to be subjected to the thermal test. A thermal shroud (enclosure) may be used for this purpose. Previously, these thermal shrouds have been constructed from wood, or metal, and insulating foam, which makes them heavy and difficult to install. Hot (or cold) air is blown in a closed loop through the shroud such that the specimen achieves a desired, constant temperature. The weight and rigid nature of the shroud can interfere with the mechanical load test. Also, if the geometry of the specimen or supporting rig changes, then extensive modifications may be required to make the shroud fit. Larger thermal shrouds of similar construction can be used to isolate an entire test specimen from ambient by forming an enclosure around the entire specimen.
There is a need for an improved thermal shroud for use in a thermal test of a specimen which overcomes at least some of the above problems.